Story at a glance

  • Aviation produces 12 percent of CO2 emissions from transportation — and the number is trending upward.
  • Airlines are trying to trim weight and use less fuel while experimenting with electric propulsion and biofuels.
  • Etihad and Boeing are working together to test a new greener aircraft and other fuel-saving techniques.

When it comes to fuel efficiency on commercial flights, Boeing's 787 Dreamliner has led the pack. Now airline Etihad plans to see just how much more efficiency it can squeeze from the aircraft, partnering with Boeing to anoint a "Greenliner" that will serve as a flying laboratory for smart fuel use.

If you weren't already thinking about how air travel contributes to your carbon footprint, you probably are now that "flying shame" has entered the vernacular. Though air travel currently accounts for 2.4 percent of the world's carbon emissions, greenhouse gases from the sector are trending upward perhaps faster than expected. As people think about how to reduce their impact on the planet, avoidable flights are on the chopping block.

Airlines are beginning to respond publicly to the pressure, acknowledging that cutting carbon pollution in a sector almost entirely dependent on fossil fuels will be, to say the least, a big challenge. At least in the short term, the industry is focused on fuel efficiency and carbon offsets to effectively plateau emissions starting in 2021 through an initiative called the Carbon Offsetting and Reduction Scheme for International Aviation, or CORSIA.

"We feel we've got to be at the forefront of that [effort]," says Adrian Gane, Etihad's director of sustainability and international affairs. "And we need to do more as the science develops."

The Abu Dhabi-based Etihad operates 37 Dreamliners, which account for more than one-third of its total fleet. The airline says the partnership with Boeing involves $215 million in cost-saving projects to overhaul landing gear, optimize maintenance planning and improve airframe components. But the thrust of its fuel-saving efforts will involve the "Etihad Greenliner," which will be unveiled early next year and serve as a test space for ideas.

Etihad and Boeing plan to form working groups between the flight operations and engineering divisions of the companies, looking for other efficiency-boosting options. The companies have already been collaborating on a biofuel produced in Abu Dhabi from plants grown in saltwater, completing a successful test flight with the fuel in January.

"We've been working with Boeing for a long time now on the biofuel project," Gane says. "We're excited to be able to use the fleet to test new techniques, with a particular emphasis on the Greenliner."

While electric planes aren't yet feasible for commercial flights, companies including Boeing and Airbus are working on technology that could eventually enable battery-powered short-haul trips. For long-haul journeys, Gane predicts, biofuels will be the fuel of choice. These kinds of advances will be paramount given that air traffic is growing far faster than fuel efficiency improvements.

“Aircraft like the Dreamliner are helping airlines improve their fuel efficiency, but air traffic is growing even faster,” says Dan Rutherford, aviation director at the International Council on Clean Transportation (ICCT). “Emissions will continue to grow until traffic growth and fuel efficiency gains are brought into balance.”

Rutherford notes that in the U.S., air traffic is growing three times as quickly as fuel efficiency is improving, and that globally, the ratio is 6-to-1. A concerned traveler's best option right now is to choose the most fuel-efficient airlines and aircraft possible — planes like the 787 Dreamliner and the A320neo, for example, have about 15 percent lower fuel burn than older designs.

The Greenliner flights next year will test biofuel, minimize single-use plastics and look for places to shave weight, for example, while also evaluating operational aspects like more efficient air control routes and later startup of engines on the ground.

"These flights will showcase a lot of what we know," Gane says, "but they'll also experiment on stuff we don't know."

It's not one big change that will get results, he adds, "but lots of little things together that will really reduce our fuel burn and contribute to the carbon reductions we're after."

Published on Dec 05, 2019